The vestibulo-ocular reflex (VOR) reduces motion of visual images on the retina by evoking eye movements in the opposite direction to head movements. A form of motor learning, known as VOR adaptation, calibrates the VOR by gradually correcting the reflex when image motion is persistently associated with head turns. VOR adaptation is essential for ensuring adequate visual acuity during head turns and for restoring proper motor and perceptual orientation in space in response to changes in the organism or its environment, such as occur with growth and development, aging, injury to the peripheral or central nervous system or the donning of a new pair of spectacles. The proposed experiments examine the neural mechanisms of VOR adaptation through a systematic analysis of the correlation between 1) the patterns of neural activity present in the circuit for the VOR during the induction of learning, 2) the altered activity in the circuit during the expression of learning, and 3) the behavioral changes that are induced. The VOR is one of many motor systems that are thought to rely on cerebellum-dependent learning to maintain normal sensorimotor function and for recovery of function following injury. The anatomy and physiology of the cerebellum is very regular across the extent of this structure, therefore, the principles uncovered in studies of VOR adaptation may be useful for the development of rational therapeutic approaches for many forms of sensorimotor dysfunction.